Display panel and method of manufacturing substrate for display panel

ABSTRACT

Disclosed are display panels and methods of manufacturing substrates. The display panel comprises a lower display substrate that includes a plurality of light emitting elements, and an upper display substrate that includes a color control layer and is on the lower display substrate. The color control layer includes a plurality of walls each of which includes a wall base including an organic material and a reflective layer including a metallic material, and the color control layer also includes a plurality of color control parts which are disposed between the plurality of walls and at least one of which includes a quantum dot. The reflective layer surrounds at least a portion of a sidewall of the wall base, which results in an increase in luminous efficiency and an improvement in brightness.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/850,046 filed on Apr. 16, 2020, which claimspriority under 35 U.S.C § 119 to Korean Patent Application Nos.10-2019-0059541 filed on May 21, 2019, and 10-2019-0165955 filed on Dec.12, 2019, in the Korean Intellectual Property Office, the disclosures ofwhich are hereby incorporated by reference in their entirety.

BACKGROUND

The present inventive concepts relate to a display panel and a method ofmanufacturing a substrate included in the display panel, and moreparticularly, to a display panel including a color conversion layer withimproved optical characteristics and a method of manufacturing asubstrate.

Various display devices are being developed for use in multimediadevices, such as smartphones, tablet computers, television sets,navigation systems, and game consoles. A color conversion layerincluding quantum-dot illuminants has been developed to improve colorreproduction and viewing angle of the display device.

It is needed to pattern a color control part including quantum-dots whenthe color conversion layer is formed, and a wall is used to distinguishthe color control parts from each other when the color control part ispatterned.

The display device has a problem of reduced brightness because the wallabsorbs or insufficiently reflects light emitted from the color controlpart. To increase brightness, it is required to improve the quality ofthe wall.

SUMMARY

Some example embodiments of the present inventive concepts provide adisplay panel with improved brightness.

Some example embodiments of the present inventive concepts provide amethod of manufacturing a substrate, which method can improvebrightness.

According to some example embodiments of the present inventive concepts,a display panel may comprise: a lower display substrate that includes aplurality of light emitting elements; and an upper display substratethat includes a color control layer and is on the lower displaysubstrate. The color control layer may include: a plurality of wallseach of which includes a wall base including an organic material and areflective layer including a metallic material; and a plurality of colorcontrol parts disposed between the plurality of walls, at least one ofthe plurality of color control parts including a quantum dot. Thereflective layer may surround at least a portion of a sidewall of thewall base.

In an embodiment, the sidewall of the wall base may be formed to have areversely tapered shape along a direction perpendicular to the lowerdisplay substrate.

In an embodiment, the display panel may further include a spacer layerwhich including an inorganic material. When viewed in a directionperpendicular to the lower display substrate, the wall base may have afirst height, the reflective layer may have a second height less thanthe first height, and the spacer layer may have a third height less thanthe first height.

In an embodiment, the reflective layer may be disposed between the wallbase and the spacer layer.

In an embodiment, the spacer layer may be disposed between the wall baseand the reflective layer.

In an embodiment, the display panel may further comprise an outer spacerlayer that surrounds the reflective layer.

In an embodiment, the spacer layer and the outer spacer layer mayinclude different materials from each other.

In an embodiment, the spacer layer may include at least one of siliconoxide, silicon nitride, silicon oxynitride, indium tin oxide, and indiumzinc oxide.

In an embodiment, the wall base may include a first-floor wall and asecond-floor wall.

In an embodiment, the first-floor wall and the second-floor wall may bein direct contact with each other.

In an embodiment, either the spacer layer or the reflective layer may bedisposed between the first-floor wall and the second-floor wall.

In an embodiment, the spacer layer and the reflective layer may surroundthe first-floor wall.

In an embodiment, the spacer layer and the reflective layer may surroundthe first-floor wall and the second-floor wall.

In an embodiment, the upper display substrate may further include acolor filter layer on the color control layer. The color filter layermay include: a plurality of light shielding layers that overlap theplurality of walls, respectively; and a plurality of color filtersdisposed between the plurality of light shielding layers.

According to some example embodiments of the present inventive concepts,a display panel may comprise: a lower display substrate that includes aplurality of light emitting elements; and an upper display substratethat includes a color control layer and is on the lower displaysubstrate. The color control layer may include a wall. The wall mayinclude a wall base and at least one functional layer, the wall baseincluding an organic material. The wall base may include: a firstsurface parallel to the lower display substrate; a second surfaceparallel to the first surface and disposed closer than the first surfaceto the lower display substrate; and a third surface that connects thefirst surface to the second surface. The functional layer may include: afirst sub-functional layer disposed adjacent to the third surface; and asecond sub-functional layer that extends from the first sub-functionallayer in a direction parallel to the first surface, the secondsub-functional layer being disposed adjacent to the first surface.

In an embodiment, a width of the wall base may increase with decreasingdistance from the lower display substrate.

In an embodiment, the function layer may include: a spacer layerincluding an inorganic material; and a reflective layer including ametallic material.

In an embodiment, the reflective layer may be disposed between thespacer layer and the third surface.

In an embodiment, the spacer layer may be disposed between thereflective layer and the third surface.

According to some example embodiments of the present inventive concepts,a method of manufacturing a substrate may comprise: forming an inorganiclayer that includes an inorganic material on a base layer; forming aplurality of wall bases which are spaced apart from each other on theinorganic layer and which increase in width along a directionperpendicular to the inorganic layer; forming a reflective layer on theinorganic layer and the wall bases, the reflective layer includingmetal; forming a spacer layer on the reflective layer on the inorganiclayer and the wall bases, the spacer layer including an inorganicmaterial; removing a portion of the spacer layer; and removing a portionof the reflective layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a perspective view showing a display panel accordingto an embodiment.

FIG. 1B illustrates a cross-sectional view showing a display panelaccording to an embodiment.

FIG. 2 illustrates a plan view showing a display panel according to anembodiment.

FIG. 3 illustrates a plan view partially showing a display panelaccording to an embodiment.

FIG. 4A illustrates a cross-sectional view taken along line I-I′ of FIG.3 , showing a display panel according to an embodiment.

FIG. 4B illustrates a plan view showing a color control layer accordingto an embodiment.

FIG. 5 illustrates a cross-sectional view taken along line I-I′ of FIG.3 , showing a display panel according to an embodiment.

FIGS. 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15 illustrate cross-sectionalviews showing a wall according to an embodiment.

FIGS. 16A, 16B, 16C, 16D, 16E and 16F illustrate cross-sectional viewsshowing a method of manufacturing a substrate according to anembodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

While the present inventive concepts are open to various modificationsand alternatives embodiments, specific embodiments thereof are shown byway of example in the drawings and will be described in detail. However,it should be understood that there is no intention to limit the presentinventive concepts to the particular embodiments disclosed, but on theother hand, the present inventive concepts are to cover allmodifications, equivalents, and alternatives falling within the spiritand scope thereof.

In this description, the phrase “directly disposed” may mean that noadditional element, such a layer, a film, a region, or a plate, ispresent between a portion and other portion of a layer, a film, aregion, a plate, or the like. For example, the phrase “directlydisposed” may mean that no additional member such as an adhesive memberis provided between two layers or members.

Like numerals indicate like components. Moreover, in the drawings,thicknesses, ratios, and dimensions of components are exaggerated foreffectively explaining the technical contents.

The term “and/or” includes one or more combinations defined byassociated components.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various components, these components shouldnot be limited by these terms. These terms are only used to distinguishone component from another component. For example, a first componentcould be termed a second component, and vice versa without departingfrom the scope of the present invention. Unless the context clearlyindicates otherwise, the singular forms are intended to include theplural forms as well.

In addition, the terms “beneath”, “lower”, “above”, “upper”, and thelike are used herein to describe one component's relationship to othercomponent(s) illustrated in the drawings. The relative terms areintended to encompass different orientations in addition to theorientation depicted in the drawings.

Unless otherwise defined, all terms used herein including technical andscientific terms have the same meaning generally understood by one ofordinary skilled in the art. Also, terms as defined in dictionariesgenerally used should be understood as having meaning identical ormeaning contextually defined in the art and should not be understood asideally or excessively formal meaning unless definitely defined herein.

It should be understood that the terms “comprise”, “include”, “have”,and the like are used to specify the presence of stated features,integers, steps, operations, components, elements, or combinationsthereof, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, components, elements, orcombinations thereof.

The following will now describe a display panel DP and a method ofmanufacturing the display panel DP according to an embodiment of thepresent inventive concepts in conjunction with the accompanyingdrawings.

FIG. 1A illustrates a perspective view showing the display panel DPaccording to an embodiment. FIG. 1B illustrates a cross-sectional viewshowing the display panel DP according to an embodiment. FIG. 2illustrates a plan view showing the display panel DP according to anembodiment. FIG. 3 illustrates a plan view partially showing the displaypanel DP according to an embodiment. FIG. 4 a illustrates across-sectional view taken along line I-I′ of FIG. 3 , showing a displaypanel DP according to an embodiment. FIG. 4 b illustrates a plan viewshowing a color control layer CCL according to an embodiment. FIG. 5illustrates a cross-sectional view taken along line I-I′ of FIG. 3 ,showing a display panel DP-1 according to an embodiment.

Referring to FIGS. 1A, 1B, and 2 , the display panel DP may be one of aliquid crystal display panel, an electrophoretic display panel, amicroelectromechanical systems (MEMS) display panel, an electrowettingdisplay panel, and an organic light emitting display panel, but thepresent inventive concepts are not limited thereto.

Although not shown, the display panel DP may further include a chassisor a molding, and may still further include a backlight unit accordingto a type of the display panel DP.

The display panel DP may include a lower display substrate 100 (referredto hereinafter as a first substrate) and an upper display substrate 200(referred to hereinafter as a second substrate) that faces and is spacedapart from the first substrate 100. A certain cell gap may be formedbetween the first substrate 100 and the second substrate 200. The cellgap may be maintained by a sealant SLM that combines the first substrate100 with the second substrate 200. The present inventive concepts,however, are not limited thereto. In another embodiment, the sealant SLMmay be omitted according to a type of the display panel DP. A gray-scaledisplay layer may be disposed between the first substrate 100 and thesecond substrate 200 for image creation. The gray-scale display layermay include a liquid crystal layer, an organic light emitting layer, oran electrophoretic layer, or the like, according to a type of thedisplay panel DP.

As shown in FIG. 1A, the display panel DP may display an image on adisplay surface DP-IS. As shown in FIG. 1B, an outer surface 200-OS ofthe second substrate 200 may be the display surface DP-IS.

The display surface DP-IS is parallel to a plane defined by a firstdirection DR1 and a second direction DR2. The display surface DP-IS mayinclude a display region DA and a non-display region NDA. A pixel PX maybe disposed on the display region DA and the pixel PX may not bedisposed on the non-display region NDA. The non-display region NDA isdisposed along a border of the display surface DP-IS. The display regionDA may be surrounded by the non-display region NDA. In an embodiment ofthe present inventive concepts, the non-display region NDA may beomitted or may be disposed only on one side of the display region DA.

A third direction DR3 indicates a normal direction to the displaysurface DP-IS, or a thickness direction of the display panel DP. Thethird direction DR3 differentiates a front surface (or top surface) anda rear surface (or bottom surface) of each layer or unit which will bediscussed below. In this description, the first, second, and thirddirections DR1, DR2, and DR3 are merely illustrative examples. Herein,first, second, and third directions are defined by the first, second,and third directions DR1, DR2, and DR3, and the same symbols areallocated thereto.

In an embodiment of the present inventive concepts, the display panel DPis illustrated to have a flat display surface DP-IS, but the presentinventive concepts are not limited thereto. The display panel DP mayinclude a curved display surface or a three-dimensional display surface.The three-dimensional display surface may include a plurality of displayregions oriented in different directions.

FIG. 2 shows a plan view showing a display panel which includes pixelsPX11 to PXnm and signal lines GL1 to GLn and DL1 to DLm. The signallines GL1 to GLn and DL1 to DLm may include a plurality of gate linesGL1 to GLn and a plurality of data lines DL1 to DLm.

Each of the pixels PX11 to PXnm is connected to a corresponding one ofthe plurality of gate lines GL1 to GLn and to a corresponding one of theplurality of data lines DL1 to DLm. Each of the pixels PX11 to PXnm mayinclude a pixel driver circuit and a display element. In addition to theplurality of gate lines GL1 to GLn and the plurality of data lines DL1to DLm, the display panel DP may further include various kinds of signallines.

The pixels PX11 to PXnm are illustrated as being arranged in a matrixshape, but the present inventive concepts are not limited thereto. Thepixels PX11 to PXnm may be disposed in a pentile shape. The pixels PX11to PXnm may be disposed in a diamond shape. A gate driver circuit GDCmay be integrated on the display panel DP through an oxide silicon gatedriver circuit (OSG) process or an amorphous silicon gate driver circuit(ASG) process.

Referring to FIG. 3 , the display panel DP may include a non-lightemitting region NPXA and light emitting regions PXA-R, PXA-G, and PXA-B.Each of the light emitting regions PXA-R, PXA-G, and PXA-B may be a zonethat emits light generated from a corresponding one of a plurality oflight emitting elements (see OEL of FIG. 4 a ). The light emittingregions PXA-R, PXA-G, and PXA-B may have different areas from each otheraccording to colors of light the light emitting regions emit when viewedon a plane. In this description, the phrase “when viewed on a plane” maymean that when viewed in the third direction DR3 (or, in the thicknessdirection). The light emitting regions PXA-R, PXA-G, PXA-B may include aplurality of groups according to the color of light emitted from theplurality of light emitting elements OEL. In this description, each ofthe light emitting regions PXA-R, PXA-G, and PXA-B may correspond to apixel.

FIG. 3 exemplarily shows that the display panel DP includes three lightemitting regions PXA-R, PXA-G, and PXA-B that emits a first light, asecond light, and a third light. For example, the display panel DPaccording to an embodiment may include a first light emitting regionsPXA-B, a second light emitting regions PXA-G, and a third light emittingregions PXA-R

In an embodiment, the first light emitting region PXA-B may be a regionthat emits a blue light having a wavelength range of 420 nm to 480 nm.The second light emitting region PXA-G may be a region that emits agreen light having a wavelength range of 500 nm to 580 nm. The thirdlight emitting region PXA-R may be a region that emits a red lighthaving a wavelength range of 600 nm to 670 nm.

For the display panel DP according to an embodiment, a plurality offirst light emitting regions PXA-B and a plurality of third lightemitting regions PXA-R may be arranged alternately along the firstdirection DR1 to constitute a first group PXG1. A plurality of secondlight emitting regions PXA-G may be arranged along the first directionDR1 to constitute a second group PXG2.

The first group PXG1 may be disposed spaced apart in the seconddirection DR2 from the second group PXG2. Each of the first and secondgroups PXG1 and PXG2 may be provided in plural. The first groups PXG1and the second groups PXG2 may be arranged alternately with each otheralong the second direction DR2.

An arrangement of the light emitting regions PXA-R, PXA-G, and PXA-Bshown in FIG. 3 may be called a pentile structure. However, on thedisplay panel DP, the arrangement structure of the light emittingregions PXA-R, PXA-G, and PXA-B is not limited to that shown in FIG. 3 .For example, in an embodiment, the light emitting regions PXA-R, PXA-G,and PXA-B may have a stripe shape in which the first light emittingregion PXA-B, the second light emitting region PXA-G, and the thirdlight emitting region PXA-R are sequentially arranged along the seconddirection DR2.

Referring to FIG. 4 a , the display panel DP may include the firstsubstrate 100 and the second substrate 200 disposed on the firstsubstrate 100.

In an embodiment, the first substrate 100 may include a base substrateBS, a circuit layer DP-CL disposed on the base substrate BS and adisplay element layer DP-OEL disposed on the base substrate BS. In anembodiment, the base substrate BS, the circuit layer DP-CL, and thedisplay element layer DP-OEL may be sequentially arranged along thethird direction DR3.

The base substrate BS may provide a base surface on which the displayelement layer DP-OEL is disposed. The base substrate BS may includeglass, metal, or synthetic resin. The base substrate BS may be rigid orflexible.

In an embodiment, the circuit layer DP-CL may be disposed on the basesubstrate BS, and may include a plurality of transistors (not shown).The transistors (not shown) may each include a control electrode, aninput electrode, and an output electrode. For example, the circuit layerDP-CL may include a switching transistor and a driving transistor thatdrive a plurality of light emitting elements OLE of the display elementlayer DP-OEL.

The display element layer DP-OEL may include a pixel defining layer PDL,a plurality of light emitting elements OEL, and a thin-filmencapsulation layer TFE. The pixel defining layer PDL may be formed of apolymer resin. For example, the pixel defining layer PDL may be formedof a polyacrylate-based or polyimide-based resin. The pixel defininglayer PDL may be formed of a polymer resin and an inorganic material.The pixel defining layer PDL may be formed of a light-absorbingmaterial, a black pigment, or a black dye. The pixel defining layer PDLmay be formed of an inorganic material. For example, the pixel defininglayer PDL may be formed of silicon nitride (SiNx), silicon oxide (SiOx),or silicon oxynitride (SiOxNy). The pixel defining layer PDL may definethe light emitting regions PXA-B, PXA-G, and PXA-R. The pixel defininglayer PDL may differentiate the light emitting regions PXA-B, PXA-G, andPXA-R from the non-light emitting regions NPXA.

The pixel defining layer PDL may overlap a wall BK in a color controllayer CCL. For example, each of a plurality of pixel defining layers PDLmay overlap each of a plurality of walls BK, respectively.

The plurality of light emitting elements OEL may each include a firstelectrode EL1, a second electrode EL2 that faces the first electrodeEL1, and an organic layer OL disposed between the first electrode EL1and the second electrode EL2. The organic layer OL may include a holetransport layer, a light emitting layer, and an electron transportlayer. The hole transport layer may include a hole injection layerdisposed adjacent to the first electrode EL1 and also include a holetransport layer disposed between the hole injection layer and the lightemitting layer, and the electron transport layer may include an electroninjection layer disposed adjacent to the second electrode EL2 and alsoinclude an electron transport layer disposed between the light emittinglayer and the electron injection layer.

The thin-film encapsulation layer TFE may be disposed on the pluralityof light emitting elements OEL, and may be disposed on the secondelectrode EL2. The thin-film encapsulation layer TFE may be directlydisposed on the second electrode EL2. The thin-film encapsulation layerTFE may be a single layer or multi layers in which a plurality of layerare vertically stacked. The configuration of the first substrate 100,however, is not limited thereto. In another embodiment, the firstsubstrate 100 may further include an input sensor (not shown) disposedon the thin-film encapsulation layer TFE. The input sensor (not shown)may be an input sensing layer or an input sensing circuit.

In an embodiment, the second substrate 200 may be disposed on the firstsubstrate 100. The second substrate 200 may include a color controllayer CCL, an inorganic layer IN, a color filter layer CFL, and a baselayer BL. Hereinafter, an example where the second substrate 200 has astructure in which the color filter layer CFL, the inorganic layer IN,and the color control layer CCL are sequentially stacked on the baselayer BL will be described. The present inventive concepts, however, arenot limited thereto.

The base layer BL may be a substrate that provides a base surface onwhich the color filter layer CFL, the inorganic layer IN, and the colorcontrol layer CCL are disposed. The base layer BL may be a glasssubstrate, a metal substrate, or a plastic substrate. However, thepresent inventive concepts are not limited thereto, and the base layerBL may include an inorganic material, an organic material, or acomposite material.

The color filter layer CFL may be disposed between the base layer BL andthe inorganic layer IN. In an embodiment, the color filter layer CFL mayinclude a light shielding layer BM and a plurality of color filtersCF-B, CF-G, and CF-R.

The light shielding layer BM may be disposed on the base layer BL. Aplurality of light shielding layers BM may be disposed spaced apart fromeach other while exposing a portion of the base layer BL. The pluralityof color filters CF-B, CF-G, and CF-R may be disposed between the lightshielding layers BM.

The plurality of color filters CF-B, CF-G, and CF-R may include a firstcolor filter CF-B, a second color filter CF-G, and a third color filterCF-R. The first color filter CF-B may transmit a first color light. Thesecond color filter CF-G may transmit a second light different from thefirst color light. The third color filter CF-R may transmit a thirdcolor light different from both the first color light and the secondcolor light.

The first color light may be light emitted from a plurality of lightemitting elements OEL. For example, the first color light may be a bluelight. The first color filter CF-B may be a blue color filter. Thesecond color filter CF-G may be a green color filter and the third colorfilter CF-R may be a red color filter. The present inventive concepts,however, are not limited thereto.

Each of the color filters CF-B, CF-G, and CF-R may include a polymericphotosensitive resin and either a pigment or a dye. The first colorfilter CF-B may include a blue pigment or dye, the second color filterCF-G may include a green pigment or dye, and the third color filter CF-Rmay include a red pigment or dye.

However, the present inventive concepts are not limited thereto, and thefirst color filter CF-B may not include a pigment or a dye. The firstcolor filter CF-B may include a polymeric photosensitive resin, but notinclude a pigment or dye. The first color filter CF-B may betransparent. The first color filter CF-B may be formed of a transparentphotosensitive resin.

In an embodiment, the light shielding layer BM may be a black matrix.The light shielding layer BM may be formed of an inorganic or organiclight shielding material including a black pigment or dye.

The light shielding layer BM may prevent light leakage and may define aboundary between adjacent ones of the color filters CF-B, CF-G, andCF-R.

The light shielding layer BM may be provided in plural, and each of theplurality of light shielding layers BM may overlap each of the pluralityof walls BK, respectively.

The color filter layer CFL may further include a low-refractive layer(not shown). The low-refractive layer (not shown) may be disposedbetween the color filter layer CFL and the color control layer CCL. Thelow-refractive layer (not shown) may have a refractive index of 1.1 to1.5. The refractive index of the low-refractive layer (not shown) may becontrolled by proportions of hollow inorganic particles and/or voids.

The color filter layer CFL may further include a buffer layer BFL. Thebuffer layer BFL may be a protective layer that protects thelow-refractive layer (not shown) or the color filter layer CF. Thebuffer layer BFL may be an inorganic layer that includes at least one ofsilicon nitride, silicon oxide, and silicon oxynitride. The buffer layerBFL may be formed of a single layer or a plurality of layers.

The constituent of the color filter layer CFL, however, is not limitedthereto. Referring to FIG. 5 , no buffer layer BFL may be included in acolor filter layer CFL-1 according to an embodiment. In addition, alight shielding layer BM-1 according to an embodiment may be formed bythe same process used to form the first color filter CF-B. For example,the light shielding layer BM-1 may be formed of an inorganic lightshielding material or an organic light shielding material including ablue pigment or a blue dye. As shown in FIG. 5 , the light shieldinglayer BM-1 may be formed at the same time with using the same materialas the first color filter CF-B.

The inorganic layer IN may be disposed on the color filter layer CFL orCFL-1. The inorganic layer IN may include at least one of silicon oxide,silicon nitride, indium tin oxide (referred to hereinafter as ITO), andindium zinc oxide (referred to hereinafter as IZO). For example, theinorganic layer IN may be silicon oxide (SiOx). When the inorganic layerIN includes silicon oxide (SiOx), the inorganic layer IN may haveincreased durability and a reduced refractive index in comparison with acase where the inorganic layer IN includes a material other than siliconoxide (SiOx). The present inventive concepts, however, are not limitedthereto. For example, in another embodiment, the inorganic layer IN mayinclude IZO.

The color control layer CCL may be disposed on the inorganic layer IN.The color control layer CCL may include a wall BK and a plurality ofcolor control parts CCP-B, CCP-G, and CCP-R. Referring FIG. 4 b , thewall BK may surround the plurality of color control parts CCP-B, CCP-G,and CCP-R in a plan view. The color control layer CCL may include aplurality of walls BK in a cross-sectional view. The plurality of wallsBK may be disposed spaced apart from each other, and each of theplurality of color control parts CCP-B, CCP-G, and CCP-R may be disposedbetween adjacent ones of the plurality of walls BK.

For example, the plurality of walls BK may define openings OH thatpartially expose the inorganic layer IN. The color control parts CCP-B,CCP-G, and CCP-R may be disposed in the openings OH. For example, thecolor control parts CCP-B, CCP-G, and CCP-R may fill the openings OHusing an inkjet process.

In an embodiment, the plurality of color control parts CCP-B, CCP-G, andCCP-R may include a first color control part CCP-B, a second colorcontrol part CCP-G, and a third color control part CCP-R. The firstcolor control part CCP-B may transmit and scatter a first light providedfrom at least one light emitting element OEL. The second color controlpart CCP-G and the third color control part CCP-R may alter a wavelengthof the first light provided from a plurality of light emitting elementsOEL and scatter the first light provided from a plurality of lightemitting elements OEL.

The first color control part CCP-B may include a base resin andscattering particles. The scattering particles may be uniformlydistributed in the base resin. The first color control part CCP-B mayinclude no quantum-dot, and may thus transmit a blue light emitted froma plurality of light emitting elements OEL. The scattering particles maybe TiO₂ or silica-based nano-particles. The present inventive concepts,however, are not limited thereto. The scattering particles may scatterlight emitted from the plurality of light emitting elements OEL.Therefore, the display panel DP may increase in viewing angle. Theprevious descriptions regarding the scattering particles included in thefirst color control part CCP-B may also be applicable to scatteringparticles included in the second and third color control parts CCP-G andCCP-R, and accordingly, detailed description thereof will be omittedbelow.

The second color control part CCP-G may include first quantum-dots, abase resin, and scattering particles. The first quantum-dots and thescattering particles may be uniformly distributed in the base resin. Thefirst quantum-dot may absorb a blue light emitted from the plurality oflight emitting elements OEL and emit a green light.

The third color control part CCP-R may include a base resin, secondquantum-dots, and scattering particles. The second quantum-dots and thescattering particles may be uniformly distributed in the base resin. Thesecond quantum-dot may absorb a blue light emitted from the plurality oflight emitting elements OEL and emit a red light. The present inventiveconcepts, however, are not limited thereto.

The light emitting regions PXA-B, PXA-G, and PXA-R of the display panelDP may overlap the plurality of color control parts CCP-B, CCP-G, andCCP-R, respectively. The light emitting regions PXA-B, PXA-G, and PXA-Rmay have their areas different from each other according to colorsemitted from the plurality of color control parts CCP-B, CCP-G, andCCP-R. For example, the light emitting region PXA-B, or a blue lightemitting region, that corresponds to the first color control part CCP-Bthrough which a blue light passes may have the largest area, and thelight emitting region PXA-G, or a green light emitting region, thatcorresponds to the second color control part CCP-G from which a greenlight is generated and emitted may have the smallest area. However, thepresent inventive concepts are not limited thereto, and the lightemitting regions PXA-B, PXA-G, and PXA-R may emit light whose colors aredifferent from a blue light, a green light, and a red light. In otherembodiments, the light emitting regions PXA-R, PXA-G, and PXA-B may havethe same area, or may have areas different from that shown above.

In an embodiment, the color control layer CCL may further include acapping layer CPL. The capping layer CPL may prevent moisture and/oroxygen (called moisture/oxygen hereinafter) from being permeated intothe color control layer CCL. For example, the capping layer CPL mayprevent the plurality of color control parts CCP-B, CCP-G, and CCP-Rfrom being exposed to moisture/oxygen.

The capping layer CPL may be formed of an inorganic material. Forexample, the capping layer CPL may be formed either of a materialincluding at least one of silicon nitride, aluminum nitride, zirconiumnitride, titanium nitride, hafnium nitride, tantalum nitride, siliconoxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, andsilicon oxynitride, or of a metal film whose light transmittance issecured. The capping layer CPL may further include an organic layer. Thecapping layer CPL may be formed of a single layer or a plurality oflayers.

FIGS. 6 to 15 illustrate cross-sectional views showing walls BK, BK-1,BK-2, BK-4, BK-5, BK-6, BK-7, BK-8, and BK-9 according to someembodiments. In detail, FIGS. 6 to 15 show cross-sections of the displaypanel DP taken along the first direction DR1 and/or a fourth directionDR4.

Hereinafter, for convenience of description, an upward direction refersto a direction indicated by the fourth direction DR4, and a downwarddirection refers to a direction indicated by the third direction DR3.

Referring to FIG. 6 , in an embodiment, the wall BK may include a wallbase BK-SB and at least one functional layer. For example, thefunctional layer may be a reflective layer MT and/or a spacer layer SP.The reflective layer MT and the spacer layer SP surround at least aportion of the wall base BK-SB.

The wall base BK-SB may have a first surface SF-B adjacent to the baselayer (see BL of FIG. 4 a or 5), a second surface SF-T that faces thefirst surface SF-B and is adjacent to the first substrate (see 100 ofFIG. 4 a ), and a third surface SF-S that connects the first surfaceSF-B to the second surface SF-T. For example, the second surface SF-Tmay be a top surface of the wall base BK-SB, the first surface SF-B maybe a bottom surface of the wall base BK-SB, and the third surface SF-Smay be a side surface of the wall base BK-SB.

In an embodiment, the wall base BK-SB may have a width WD that increasesas approaching the second surface SF-T from the first surface SF-B. Forexample, a maximum width W1 of the first surface SF-B may be less than amaximum width W2 of the second surface SF-T. In this description, thewidth WD of the wall base BK-SB may refer to a cross-sectional length ofthe wall base BK-SB measured in the first direction DR1.

In an embodiment, in a cross-sectional view, the wall base BK-SB has anobtuse angle θ between the third surface SF-S and the first surfaceSF-B. Hereinafter, a shape of the wall base BK-SB having the width WDand the angle θ discussed above will be referred to as a reversetrapezoidal shape. The sidewall of the wall base is formed to have areversely tapered shape along a direction perpendicular to the lowerdisplay substrate. The previous descriptions regarding the width WD andthe angle θ of the wall base BK-SB shown in FIG. 6 are also identicallyapplicable to the embodiments of FIGS. 7 to 15 , and accordingly,repetitive descriptions thereof will be omitted.

In an embodiment, the wall base BK-SB may include a polymer resin and arepellent additive. For example, a concentration of the repellentadditive may be greater in an upper portion of the wall base BK-SB thanin a lower portion of the wall base BK-SB. Therefore, liquid repellencymay be given to the second surface SF-T or the top surface of the wallbase BK-SB. In other words, the second surface SF-T or the top surfaceof the wall base BK-SB may have hydrophobic characteristic.

The wall base BK-SB may have a low surface energy at a portion having ahigh concentration of the repellent additive. The wall base BK-SB mayhave a high surface energy at a portion having a low concentration ofthe repellent additive. Therefore, in an embodiment, the wall BK mayhave a surface energy that is lower at the second surface SF-T than atthe third surface SF-S. For example, the surface energy at the secondsurface SF-T of the wall base BK-SB may be equal to or less than 20dyne/cm, and the surface energy at the third surface SF-S of the wallbase BK-SB may be equal to or greater than 30 dyne/cm.

Therefore, the wall base BK-SB according to an embodiment may haveliquid repellency at the second surface SF-T or the top surface thereof,and may have no liquid repellency at the third surface SF-S or the sidesurface thereof. Because the second surface SF-T has hydrophobiccharacteristic, during the formation of the color control layer CCL, acomposition of a plurality of color control parts CCP-B, CCP-G, andCCP-R may not formed on the second surface SF-T, but may flow toward thethird surface SF-S and easily fill the opening OH between a plurality ofwalls BK using an inkjet process. The composition of a plurality ofcolor control parts CCP-B, CCP-G, and CCP-R may include a base resin,scattering particles, and quantum-dots discussed above.

Referring still to FIG. 6 , the reflective layer MT and the spacer layerSP may surround at least a portion of the third surface SF-S of the wallbase BK-SB. For example, the reflective layer MT may be in contact withthe third surface SF-S, and the spacer layer SP may be in contact withthe reflective layer MT.

In an embodiment, the reflective layer MT may include a firstsub-reflective layer MT0-1 and a second sub-reflective layer MT0-2. Forexample, the first sub-reflective layer MT0-1 may surround the thirdsurface SF-S or the side surface of the wall base BK-SB. The firstsub-reflective layer MT0-1 may be, for example, in contact with thethird surface SF-S or the side surface of the wall base BK-SB. Thesecond sub-reflective layer MT0-2 may extend from the firstsub-reflective layer MT0-1 in a direction parallel to the first surfaceSF-B and may be disposed adjacent to the first surface SF-B.

The reflective layer MT may reflect light. For example, light emittedfrom a plurality of color control parts CCP-B, CCP-G, and CCP-R may bereflected from the reflective layer MT and may travel outwardly throughthe base layer BL. The reflected light may pass through the base layerBL and may be recognized by users, and may determine brightness of thedisplay device DD. For example, the larger quantity of light reflectedoutwardly through the base layer BL, the higher brightness of thedisplay device DD.

The reflective layer MT may include metal, for example, aluminum (Al).The present inventive concepts, however, are not limited thereto. Whenthe reflective layer MT includes aluminum, the reflective layer MT mayhave reflectance equal to or greater than 90%. Aluminum included in thereflective layer MT may contact oxygen and may then be oxidized to formaluminum oxide (AlO₃). When aluminum oxide (AlO₃) is formed, thereflectance of the reflective layer MT may be reduced to 70% to 80%. Toprevent oxidation of the reflective layer MT, the spacer layer SP may bedisposed to cover the reflective layer MT.

In an embodiment, the spacer layer SP may surround the reflective layerMT. For example, the reflective layer MT may be disposed between thespacer layer SP and the third surface SF-S of the wall base BK-SB. Thespacer layer SP may prevent the deterioration in reflectance of thereflective layer MT, while surrounding the reflective layer MT.

The spacer layer SP may include a first sub-spacer layer SP0-1 and asecond sub-spacer layer SP0-2.

The first sub-spacer layer SP0-1 may be disposed to cover the firstsub-reflective layer MT0-1. For example, the first sub-spacer layerSP0-1 may be in contact with the first sub-reflective layer MT0-1. Thesecond sub-spacer layer SP0-2 may extend from the first sub-spacer layerSP0-1 in a direction parallel to the base layer BL, and may be disposedto cover the second sub-reflective layer MT0-2.

The spacer layer SP may include an inorganic material. For example, thespacer layer SP may include at least one of silicon oxide, siliconnitride, silicon oxynitride, ITO, and IZO. For example, the inorganicmaterial may be silicon oxide (SiOx). The present inventive concepts,however, are not limited thereto. When the spacer layer SP includessilicon oxide (SiOx), the spacer layer SP may have transmittance equalto or greater than 95%. In addition, silicon oxide (SiOx) may haveresistance to etching, and thus may remain without being damaged in anetching process.

In an embodiment, the functional layer may refer to the reflective layerMT and the spacer layer SP.

The spacer layer SP including silicon oxide (SiOx) may have hightransmittance and a low reflective index. For example, light emittedfrom a plurality of color control parts CCP-B, CCP-G, and CCP-R may passthrough the spacer layer SP and may reach the reflective layer MT. Thelight may be reflected from the reflective layer MT and then may traveloutwardly through the base layer BL. In addition, because the wall BKhas a reverse trapezoidal shape, it may be possible to increase a lightoutput ratio, or the ratio of light outwardly reflected through the baselayer BL to light emitted from a plurality of color control parts CCP-B,CCP-G, and CCP-R. Therefore, the display panel DP may increase inluminous efficiency and brightness.

In the wall BK according to an embodiment, the wall base BK-SB may havea first height H1. The first height H1 may be a value measured from thefirst surface SF-B to the second surface SF-T in a directionperpendicular to the first surface SF-B. For example, the first heightH1 may range from 15 μm to 20 μm. The present inventive concepts,however, are not limited thereto.

In an embodiment, the reflective layer MT may have a second heightH2-MT. The second height H2-MT may be a height of the reflective layerMT measured in the fourth direction DR4 from the first surface SF-B. Thesecond height H2-MT may be less than the first height H1.

In an embodiment, the spacer layer SP may have a third height H2-SP. Thethird height H2-SP may be a height of the spacer layer SP measured inthe fourth direction DR4 from the first surface SF-B. The third heightH3-SP may be less than the first height H1.

FIG. 6 shows that the second height H2-MT and the third height H2-SP arethe same, but the second height H2-MT and the third height H2-SP are notlimited to that shown and may be changed depending on processes.

Referring to FIG. 7 , the wall BK-1 according to an embodiment mayinclude a reflective layer MT-1, a spacer layer SP-1, and a wall baseBK-SB. To be specific, the spacer layer SP-1 may include a firstsub-spacer layer SP1-1 and a second sub-spacer layer SP1-2. For example,the first sub-spacer layer SP1-1 may surround the third surface SF-S orthe side surface of the wall base BK-SB. The second sub-spacer layerSP1-2 may extend from the first sub-spacer layer SP1-1 in a directionparallel to the first surface SF-B, and may be disposed in contact withthe first surface SF-B.

To be specific, the reflective layer MT-1 may surround the spacer layerSP-1. For example, the spacer layer SP-1 may be disposed between thereflective layer MT-1 and the third surface SF-S of the wall base BK-SB.The reflective layer MT-1 may include a first sub-reflective layer MT1-1and a second sub-reflective layer MT1-2.

The first sub-reflective layer MT1-1 may be disposed to cover the firstsub-spacer layer SP1-1. The second sub-reflective layer MT1-2 may extendfrom the first sub-reflective layer MT1-1 in a direction parallel to thefirst surface SF-B, and may be disposed to cover the first sub-spacerlayer SP1-2.

The previous description regarding to the second height H2-MT of FIG. 6may be identically applicable to a second height H3-MT.

The previous description regarding to the third height H2-SP of FIG. 6may be identically applicable to a third height H3-SP.

FIG. 7 shows that the second height H3-MT and the third height H3-SP arethe same, but the second height H3-MT and the third height H3-SP are notlimited to that shown and may be changed depending on processes. Theexplanation discussed above in FIG. 6 may be identically applicable toother configurations.

Referring to FIG. 8 , the wall BK-2 may be configured such that a spacerlayer SP-2 may be disposed between a reflective layer MT-2 and the thirdsurface SF-S. The spacer layer SP-2 may further include a thirdsub-spacer layer SP2-3. The third sub-spacer layer SP2-3 may cover thesecond surface SF-T or the top surface of the wall base BK-SB.

A second height H4-MT may be a length measured in the fourth directionDR4 from a plane parallel to the first surface SF-B to the farthestportion of the reflective layer MT-2. The second height H4-MT may beless than the first height H1.

A third height H4-SP may be a length measured in the fourth directionDR4 from a plane parallel to the first surface SF-B to the farthestportion of the spacer layer SP-2. The third height H4-SP may be greaterthan the first height H1. The explanation discussed above in FIG. 6 maybe identically applicable to other configurations.

Referring to FIG. 9 , the wall BK-3 according to an embodiment mayinclude one functional layer. For example, a reflective layer MT-3 maybe included in the wall BK-3 according to an embodiment. A reflectivelayer MT-3 may be disposed adjacent to the third surface SF-S of thewall base BK-SB. The reflective layer MT-3 may further include a thirdsub-reflective layer MT3-3. The third sub-reflective layer MT3-3 maycover the second surface SF-T or the top surface of the wall base BK-SB.

A second height H5-MT may be a length measured in the fourth directionDR4 from a plane parallel to the first surface SF-B to the farthestportion of the reflective layer MT-3. The second height H5-MT may begreater than the first height H1. The explanation discussed above inFIG. 6 may be identically applicable to other configurations.

Referring to FIG. 10 , the wall BK-4 according to an embodiment mayinclude a wall base BK-SB, a reflective layer MT-4, a spacer layer SP-3.The reflective layer MT-4 may surround the wall base BK-SB. The spacerlayer SP-3 may surround the reflective layer MT-4. In addition, the wallbase BK-SB of the wall BK-4 according to an embodiment may include afirst sub-wall base BK-S11, a second sub-wall base BK-S12, and a thirdsub-wall base BK-S13. For example, the first sub-wall base BK-S11 mayhave a width WD that decreases in a direction from a first surface SF-Btoward a second surface SF-T that faces the first surface SF-B. In thisdescription, the width WD may indicate a length in the first directionDR1 on a cross-sectional view of the wall base BK-SB.

The second sub-wall base BK-S12 may have a width that increases in adirection from the first sub-wall base BK-S11 toward the second surfaceSF-T. A concave section UC may be formed at a portion where the firstsub-wall base BK-S11 is connected to the second sub-wall base BK-S12.

The third sub-wall base BK-S13 may have a width that decreases in adirection from the second sub-wall base BK-S12 toward the second surfaceSF-T. The third sub-wall base BK-S13 may have a curved shape at a topedge portion thereof. When viewed in cross-section perpendicular to thefirst surface SF-B, the third sub-wall base BK-S13 may include a flatpart FP and curved parts CP1 and CP2. For example, the flat part FP mayhave a flat top surface. The curved parts CP1 and CP2 may be disposed onopposite sides of the flat part FP. The curved parts CP1 and CP2 mayhave curve-shaped portions whose widths decrease in a direction from thesecond sub-wall base BK-S12 toward the second surface SF-T. For example,a first curved part CP1 may be disposed on one side of the flat part FP.A second curved part CP2 may be symmetric to the first curved part CP1about the flat part FP, and may be disposed on the other side of theflat part FP.

In an embodiment, the reflective layer MT-4 and the spacer layer SP-3may surround the wall base BK-SB. Because the wall base BK-SB includesthe curved parts CP1 and CP2, the reflective layer MT-4 and the spacerlayer SP-3 may have their curved surfaces.

Referring to FIG. 11 , the wall BK-5 according to an embodiment mayinclude three functional layers. For example, the wall BK-5 may furtherinclude an outer spacer layer SP-OT in addition to the spacer layer SP-1and the reflective layer MT-1 includes in the wall BK-1 of FIG. 7 . Theouter spacer layer SP-OT may surround and prevent the reflective layerMT-1 from being oxidized.

In an embodiment, each of the spacer layer SP-1 and the outer spacerlayer SP-OT may include an inorganic material. To be specific, thespacer layer SP-1 and the outer spacer layer SP-OT may independentlyinclude at least one of silicon oxide, silicon nitride, siliconoxynitride, ITO, and IZO. For example, the spacer layer SP-1 may includesilicon oxide (SiOx). The outer spacer layer SP-OT may include IZO. Theexplanation discussed above in FIG. 7 may be identically applicable toother configurations.

Referring to FIGS. 12 and 13 , the walls BK-6 and BK-7 according toembodiments may correspondingly include wall bases BK-SB1 and BK-SB2each of which has a multiple layer. For example, each of the wall basesBK-SB1 and BK-SB2 may include a first-floor wall BK-1F and asecond-floor wall BK-2F. In an embodiment, each of the first-floor wallBK-1F and the second-floor wall BK-2F may include a polymer resin and arepellent additive. A concentration of the repellent additive includedin the second-floor wall BK-2F may be greater than that of the repellentadditive included in the first-floor wall BK-1F.

As shown in FIG. 12 , the wall BK-6 according to an embodiment may beconfigured such that the second-floor wall BK-2F is disposed on the wallBK-2 illustrated in FIG. 8 .

As shown in FIG. 13 , the wall BK-7 according to an embodiment may beconfigured such that the second-floor wall BK-2F is disposed on the wallBK-5 illustrated in FIG. 11 .

However, the present inventive concepts are not limited thereto, and thesecond-floor wall BK-2F may be disposed on one of the walls BK, BK-1,and BK-3 illustrated in FIGS. 6, 7, and 9 .

As shown in FIG. 12 , a functional layer may be disposed between thefirst-floor wall BK-1F and the second-floor wall BK-2F. For example, thespacer layer SP-2 may be provided between the first-floor wall BK-1F andthe second-floor wall BK-2F. The present inventive concepts, however,are not limited thereto.

Because the wall bases BK-1F and BK-2F include a multiple layer, thewalls BK-6 and BK-7 may be adjusted in height. An increase in height ofwall may raise heights of a plurality of color control parts CCP-B,CCP-G, and CCP-R between the walls. Therefore, the display panel DP mayincrease in luminous efficiency and brightness.

Referring to FIGS. 14 and 15 , each of the walls BK-8 and BK-9 accordingto embodiments may be configured such that the first-floor wall BK-1Fand the second-floor wall BK-2F are in contact with each other. Forexample, the second-floor wall BK-2F may be in direct contact with thesecond surface SF-T of the first-floor wall BK-1F. In an embodiment, afunctional layer may surround sidewalls of all of the first- andsecond-floor walls BK-1F and BK-2F.

As shown in FIG. 14 , the wall BK-8 according to an embodiment mayinclude a spacer layer SP-4, a first-floor reflective layer MT-1F, and asecond-floor reflective layer MT-2F. The spacer layer SP-4 may surroundthe first-floor wall BK-1F and the second-floor wall BK-2F at the sametime. The first-floor reflective layer MT-1F may be disposed on thefirst-floor wall BK-1F and may surround the spacer layer SP-4. Thesecond-floor reflective layer MT-2F may be disposed on the second-floorwall BK-2F and may surround the spacer layer SP-4. The first-floorreflective layer MT-1F and the second-floor reflective layer MT-2F arenot directly connected to each other but includes a disconnected portionat a region corresponding to an interface between the first-floorreflective layer MT-1F and a second-floor reflective layer MT-2F.

As shown in FIG. 15 , the wall BK-9 according to an embodiment mayinclude a spacer layer SP-4, a first-floor reflective layer MT-1F, asecond-floor reflective layer MT-2F, a first-floor outer spacer layerSP-OT1, and a second-floor outer spacer layer SP-OT2. The first-floorouter spacer layer SP-OT1 may be disposed on the first-floor wall BK-1Fand may surround the first-floor reflective layer MT-1F. Thesecond-floor outer spacer layer SP-OT2 may be disposed on thesecond-floor wall BK-2F and may surround the second-floor reflectivelayer MT-2F. The first-floor outer spacer layer SP-OT1 and thesecond-floor outer spacer layer SP-OT2 are not directly connected toeach other but includes a disconnected portion at a region correspondingto an interface between the first-floor reflective layer MT-1F and asecond-floor reflective layer MT-2F. Because the first-floor outerspacer layer SP-OT1 and the second-floor outer spacer layer SP-OT2respectively surround the first-floor reflective layer MT-1F andsecond-floor reflective layer MT-2F, the first- and second-floorreflective layers MT-1F and MT-2F may be prevented from being oxidizedand the wall BK-9 may increase in reflectance.

FIGS. 16A to 16F illustrate cross-sectional views showing a method ofmanufacturing a substrate according to an embodiment. The substrate maybe the second substrate 200 discussed above.

The method of manufacturing the substrate according to an embodiment mayinclude a step of forming an inorganic layer IN on a base layer BL, astep of forming a plurality of wall bases BK-SB which are disposedspaced apart from each other and which increase in width along adirection perpendicular to the inorganic layer IN on the inorganic layerIN, a step of forming a reflective layer MT which is disposed on theinorganic layer IN and the wall bases BK-SB and which includes metal, astep of forming a spacer layer SP on the inorganic layer IN and the wallbases BK-SB on which the reflective layer MT is formed, a step ofremoving a portion of the spacer layer SP, and a step of removing aportion of the reflective layer MT.

The sequence of the manufacturing method may be changed according to thestructure of a wall BK, and FIGS. 16A to 16F show a method ofmanufacturing the wall BK of FIG. 6 according to an embodiment.

Referring to FIG. 16A, the inorganic layer formation step may includeforming the inorganic layer IN including an inorganic material on thebase layer BL. The inorganic layer IN may be deposited on the base layerBL using Chemical vapor deposition (CVD). The inorganic layer IN mayinclude at least one of silicon oxide, silicon nitride, siliconoxynitride, ITO, and IZO.

Referring to FIG. 16B, the wall base formation step may form a pluralityof wall bases BK-SB that are spaced apart from each other on theinorganic layer IN. The plurality of wall bases BK-SB may be a singlewall base connected to one another which has a plurality of openingsformed in the sigla wall base to expose the inorganic layer IN whichcorresponds to the plurality of color control parts CCP-B, CCP-G, andCCP-R. The wall base BK-SB may include a polymer resin and a repellentadditive. The wall base BK-SB may increase in width WD along a directionperpendicular to a surface of the inorganic layer IN. In thisdescription, the width WD may indicate a length in the first directionDR1 on a cross-sectional view of the wall base BK-SB. The wall baseBK-SB may be formed by a photoresist process.

Referring to FIG. 16C, the reflective layer formation step may form thereflective layer MT on the inorganic layer IN and the wall bases BK-SB.The reflective layer MT may include metal. For example, the reflectivelayer MT may include aluminum.

In an embodiment, the reflective layer MT may be formed using asputtering process or a CVD process on the inorganic layer IN and thewall bases BK-SB.

Referring to FIG. 16D, the spacer layer formation step may form thespacer layer SP on the reflective layer MT on the inorganic layer IN andthe wall bases BK-SB. The spacer layer SP may include an inorganicmaterial. For example, the spacer layer SP may include at least one ofsilicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride(SiOxNy), ITO, and IZO. The spacer layer SP may include, for example,silicon oxide. The spacer layer may be formed using a CVD process. Thepresent inventive concepts, however, are not limited to that discussedabove. The spacer layer SP including silicon oxide (SiOx) may haveresistance to etching and high transmittance equal to or greater than95%.

Referring to FIG. 16E, the spacer layer etching step may include thatthe spacer layer SP is etched in a direction perpendicular to the baselayer BL. For example, a dry etching process, for example, Reactive IonEtching (RIE) may be performed on the spacer layer SP. The dry etchingprocess may be executed in such a way that an etching target is etchedby ions, plasma, or radicals. For example, the dry etching process maybe a physical etching process which uses the ions, the plasma, or theradicals. The physical etching process may be executed in such a waythat an etching target is collided with ions to etch a surface of theetching target.

Unlike wet etching processes, the dry etching process may be ananisotropic etching process. For example, an etching target may bedirectionally etched in the anisotropic etching process. When the spacerlayer SP is anisotropically etched, the spacer layer SP may be etched ina direction perpendicular to the base layer BL. When the wall base BK-SBhas a reverse trapezoidal shape according to an embodiment, theanisotropic etching process may remove portions of the spacer layer SPthat are disposed on a plurality of wall bases BK-SB and/or portions ofthe spacer layer SP that are disposed between a plurality of wall basesBK-SB.

Referring to FIG. 16F, the reflective layer etching step may includethat the reflective layer MT is etched in a direction perpendicular tothe base layer BL. For example, the reflective layer MT may be etched bya dry etching process or a wet etching process. The dry etching processmay be, for example, a physical etching process. For example, a chlorideion (Cl⁻) may react with aluminum (Al) of the reflective layer MT whichis exposed, such that a surface of aluminum may be partially removedwhile aluminum chloride is produced. The wet etching process may use anetchant to etch a surface of an etching target.

According to exemple embodiment, since the wall base BK-SB has aninverse taper shape, a first length LL1 is longer than a second lengthLL2. The first length LL1 is a length measured up from a central axis PLof the wall base BK-SB to one end of the first sub-spacer layer SP0-1.The second length LL2 is a length measured up from a central axis PL ofthe wall base BK-SB to one end of the second sub-spacer layer SP0-2.

A display panel according to an embodiment may be configured such that awall of an upper display substrate may include a reflective layer and aspacer layer, which may result in an increase in luminous efficiency andan improvement in brightness.

Although the embodiments have been described with reference to a numberof illustrative examples thereof, it will be understood by those ofordinary skill in the art that various changes in form and details maybe made without departing from the spirit and scope of the presentinventive concepts as set forth in the following claims.

Thus, the technical scope of the present inventive concepts is notlimited by the embodiments and examples described above, but by thefollowing claims.

What is claimed is:
 1. A method of manufacturing a substrate, the methodcomprising: forming an inorganic layer including an inorganic materialon a base layer; forming a plurality of wall bases which are spacedapart from each other on the inorganic layer and which increase in widthalong a direction perpendicular to the inorganic layer; forming areflective layer on the inorganic layer and the wall bases, thereflective layer including metal; forming a spacer layer on theinorganic layer and the wall bases, the spacer layer including aninorganic material; removing a portion of the spacer layer; and removinga portion of the reflective layer.
 2. The method of claim 1, wherein theportion of the reflective layer is removed by a dry etching or a wetetching.
 3. The method of claim 1, wherein the potion of the spacerlayer is removed by a dry etching.
 4. The method of claim 1, wherein thewall bases has a height greater than a height of the reflective layerfrom which the portion of the reflective layer is removed.
 5. The methodof claim 4, wherein the spacer layer has a height less than the heightof the wall bases.
 6. The method of claim 1, wherein the reflectivelayer is disposed between the wall base and the spacer layer.
 7. Themethod of claim 1, wherein the spacer layer is disposed between the wallbase and the reflective layer.
 8. The method of claim 7, furthercomprising forming an outer spacer layer which surrounds the reflectivelayer, wherein the reflective layer is disposed between the spacer layerand the outer spacer layer.
 9. The method of claim 8, wherein the spacerlayer and the outer spacer layer include different materials from eachother.
 10. The method of claim 1, wherein each of the wall basesincludes: a first surface parallel to the base layer; a second surfaceparallel to the first surface and disposed closer than the first surfaceto the base layer; and a third surface that connects the first surfaceto the second surface, wherein the reflective layer and the spacer layerare disposed on the third surface.
 11. The method of claim 1, furthercomprising forming a floor wall on the wall bases, wherein the floorwall increases in width along the direction perpendicular to theinorganic layer.
 12. The method of claim 1, wherein the spacer layerincludes at least one of silicon oxide, silicon nitride, siliconoxynitride, indium tin oxide, and indium zinc oxide.